blob: 4b3533b847745657304c1b46a2b4fba48a95522f (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
/*******************************************************************************
* Copyright (c) 2009, 2010 Cloudsmith Inc. and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Cloudsmith Inc. - initial API and implementation
*******************************************************************************/
package org.eclipse.equinox.p2.metadata.expression;
import java.util.Iterator;
import org.eclipse.equinox.p2.metadata.index.IIndexProvider;
/**
* This is an expression that will need access to the global variable
* <code>everything</code>.
* @since 2.0
*/
public interface IContextExpression<T> extends IExpression {
/**
* <p>Creates a new context to be passed to a subsequent evaluation. The context
* will have the variable 'everything' set to an expression that represents
* the <code>everything</code> iterator filtered for instances of <code>elementClass</code>.</p>
* <p>The values of the iterator will be copied if necessary (when everything is referenced
* more then once).</p>
* @param elementClass the class of the iterator elements
* @param indexProvider The index provider that represents all queried material.
* @return A new evaluation context.
*/
IEvaluationContext createContext(Class<? extends T> elementClass, IIndexProvider<T> indexProvider);
/**
* <p>Creates a new context to be passed to a subsequent evaluation. The context
* will have the variable 'everything' set to an expression that represents
* the <code>everything</code> iterator filtered for instances of <code>elementClass</code>.</p>
* <p>The values of the iterator will be copied if necessary (when everything is referenced
* more then once).</p>
* @param elementClass the class of the iterator elements
* @param everything The iterator that represents all queried material.
* @return A new evaluation context.
*/
IEvaluationContext createContext(Class<? extends T> elementClass, Iterator<T> everything);
/**
* Returns the parameters that this context expression was created with.
* @return An array of parameters, possibly empty but never <code>null</code>.
*/
Object[] getParameters();
/**
* Evaluate the expression and return the expected collection result as an iterator
* @param context The evaluation context
* @return The result of the evaluation.
*/
Iterator<T> iterator(IEvaluationContext context);
}
|
